MT 190 HW #7 Solution p.1
MT190 HW #7 Solution
Q1. p.118 # 4
Allie made the mistake that regrouping a hundred gives 10 ones. It should be 10 tens instead. Her
work should show the 10 tens, then she can regroup 1 ten into 10 ones so she can subtract 9 ones

MT190 HW#11 Solution p. 1
MT190 HW # 11 Solution
Q1.
i) The 3 common confusions are: confounding division by with division by 2,
confounding division by with multiplication by and confusing the three
concepts.
ii) It is a how many groups problem. It is no

MT190 HW#8 Solution p.1
MT190 HW # 8 Solution.
2. Express the decimal 312.872291 into fraction.
312.872291 = 312
872291
(by counting the number of digits on the right of the decimal point)
1000000
or we can show in great details:
312.872291
8
7
2
2
9
1
+

HW #9 Solution p.1
MT190 HW #9 Solution
Q1. p.146 # 7
a)
b) After we choose the pair (from part a), we still have two options to put them on the
left and right foot. For example, after we choose green sock and a red striped sock, we
can either put the gre

HW #10 Solution p.1
MT190 HW#10 Solution
Q1. Detailed reading of Mas book: Chapter 3 p.47 to p.55 (just before the section on
The U.S. Teachers representation of division by fractions). We will have a short quiz on
these on Friday.
Q2.
a) Use the partial-

MT 190 HW #6 Solution p.1
MT190 HW # 6 Solution
Q1. p.68 # 20 part a only
Ans: 3/8 of a cup
1 cup of water
(4 large parts)
cup of water
(3 large parts)
of cup of water
taken out
water left
(3 small parts)
Now, look back that the 1 cup of water consists

MT190 HW#5 Solution p.1
MT190 HW # 5 Solution
Q1:
a) Conceptually directed group: the students did not understand the rationale of the
algorithm and place values.
Procedurally directed group: it was a problem of carrying out the lining-up procedure.
b)
On

MT190 HW#1 Solution p.1
MT190 HW #2 Solution
Q1:
i) Ans: 0
ii) Ans: negative integer, for example -3
1
iii) Ans: for example
2
iv) Ans: impossible. Every integer is automatically a rational number
v) Ans: there are many numbers that can not be expressed a

MT190 HW#2
(Due Friday 9/20)
Q1 a) Describe very briefly at least three mistakes/missteps that many teachers made when they
teach about 62 49 = 13.
Some of the common mistakes are:
1) The teacher emphasized on the procedural understanding instead of conce

HW #3 Solution p.1
MT190 HW #3 Solution
Q1. p.57 #1
Michael needs to learn that the whole can be comprised of a set of objects. In this case,
the whole is 15 marbles, and 5 marbles are just 1/3 of the whole set of marbles. The set
of dark marbles is indee

MT190 HW#4 Solution
MT190 HW # 4 Solution
Q1. p.68 #19 (Partial Ans: 3/8 5/12 of a cup)
a)
Or, you can use the following diagrams:
A cup of water
(12 parts)
of a cup of water
(9 parts)
1/3 of a cup of water
(4 parts)
Remaining is 9 4 =5 parts out of 12 p